The 87-year-old Mandurah man was in bed asleep when he awoke to the intruders searching through the rooms of his Dudley Park home about 2am yesterday.
Upon investigating, the intruders struck the man to the back of his head, knocking him unconscious.
After regaining consciousness, the man called police for assistance and was taken to hospital.
His home of 23 years was left ransacked.
Detective First Class Constable Matthew Mackay said police were treating the aggravated burglary with the “utmost seriousness”.
“This is definitely a serous and horrible offence that occurred against an elderly and vulnerable member of our community,” he said.
“We’ve allocated significant resources throughout the district, in the form of forensic officers. We have multiple units that are out there doing everything we can to apprehend these offenders.”
Security cameras caught the offenders peering into a neighbour’s car and looking through a nearby letterbox before they entered the victim’s house.
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Neighbours living on the street have told 9News they are “shocked”.
“It was on our street? It doesn’t happen here, it’s surprising,” resident Alison Homsey said.
The elderly man has been described a really “great guy and a dear man”.
“He helps take everyone’s paper in for him if they’re not home,” resident Valorie McNamara said.
“He is a really nice man and it’s very sad.”
Relatives remain by the man’s side in hospital, where it’s expected he will stay for days.
“He’s described himself as feeling sore and shaken up. But he is recovering well,” Detective First Class Constable Mackay said.
“He surrounded by family that are providing him with support.”